1. Technical Field
Embodiments of the present invention include a projector, a screen, a projector system, and a scintillation removing apparatus. In particular, an embodiment of the invention relates to a projector that includes a mechanism for removing scintillation to be generated upon image display
2. Related Art
There is known a projector that illuminates a spatial light modulator, such as a liquid crystal light valve or the like, with a light source, and projects image light modulated by the spatial light modulator on a screen using a projection optical system, such as a projection lens or the like, on magnified scale. In such a projector, when display is performed on the basis of image light, light interference may occur in a scatterer, such as the screen or the like. Accordingly, a phenomenon that bright and dark points are distributed in stripe or spot patterns, so-called scintillation (or speckle), may occur.
Scintillation is a factor having a bad effect, for example, in causing an observer to feel a feeling of irregularity and causing inconvenience when the observer views images. Particularly, since laser light has high interference. scintillation may easily occur. In recent years, even in a lamp light source, wit the improvement of short arc, interference becomes high, and a technology for removing scintillation becomes important. In a related art laser projection type display device, a light diffuser, such as a holographic light diffuser, is interposed between a laser light source and a spatial light modulator. Then, the light diffuser moves linearly, circularly, or randomly by a motion applying unit, such as an electric motor or the like, thereby removing scintillation. This technology has been suggested in JP-A-2003-98476. This technology moves the light diffuser to dynamically change a speckle pattern (interference pattern) such that the speckle pattern is not caught by a human's eve.
In the technology disclosed in JP-A-2003-98476, as the motion applying unit of the light diffuser, an electric motor, a vibrating motor, and a linear actuator are exemplified. However, these units have a problem in that responsibility in moving the light diffuser at high speed is lacking. Further, in view of vibration or noise, power consumption, and the like, many problems exist. In addition, it is rarely put to practical use. Accordingly, even though the above technology is used, scintillation may not be effectively removed, and a user may not feet satisfaction in view of practicality.